From patchwork Fri Dec 10 06:55:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12695573 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F174C433EF for ; Fri, 10 Dec 2021 07:04:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=KnvsvUfDeYwbOswgW5uXKP1XQpDA+jjyGW6xyhthEEg=; b=N1I/SqOlKV8Qcp 0l5kChbuoS+2pJOx2IoIBcC2n6SYRuwypSvyKB3y0Tmj/5TWOtGgduiBb1/v6MkPyOctNFrbLEiEY DxbI3qujVWks04yBsDD/+WnVz3CqdAzlzpnzm/B7dGLY6YYqaDU7SFSKWsRJx15yxb1erYsdEMSyY S0OHyxGph3HdC6MxUBbX58dOWZNUEx2eyUtmDGN1oVqFcEfGf1jb3y6+2oIMZuPJYN3viHYCZMC9O OxP9J78+Zwd2rmLBYn3Wfnc/eCOrg/cFVZhZgeZ0VP73zw19DLM056OS2eE6gVb4f1Ar4eyqgrVna Sx6qXtDNsk38hnAfiKVA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvZvU-000yRy-0k; Fri, 10 Dec 2021 07:02:40 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvZq9-000viI-0O; Fri, 10 Dec 2021 06:57:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From: Sender:Reply-To:Content-ID:Content-Description; bh=Q+OxcJDNHo5SyJiWeVtFPLSYAJ/30FsqZ0LmgkvcxYY=; b=cyHJhWapZAqfu2OZQXOKjt4ihw PvwmTShbxWy5rsG8jjuMbGkm1STpQ0WfYIxmR8Y6WkKsvgFDox5u5tIAeO8BGe0Hc5IcA1o3Y4I9t g6BF2BynN3KBM64VZXxL7YDQr284SLcwYx6yFnJdsXZ9XiojpzH3i0sBYBZa5hkTlnUkUXjuXQQuV h+Co8g1E5dhT6moXmeAyLJWR7cjvMPlAkjslUUoyR5I+hnmP0nsYhmJcsb+8oBMVrHRkYWTiyqOUN HhDxl6uUuM4mcGtq3mCIGXWSJ59Wkx8tIlCMmCGJJZqhk6qGJPX1MZUKTeSz178IY/PL2pgEd6sZm cP/raYew==; Received: from szxga03-in.huawei.com ([45.249.212.189]) by desiato.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvZpq-000WJz-Ug; Fri, 10 Dec 2021 06:57:07 +0000 Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4J9M8T5KjXz8vnT; Fri, 10 Dec 2021 14:54:33 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 14:56:41 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Fri, 10 Dec 2021 14:56:40 +0800 From: Zhen Lei To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , , Catalin Marinas , "Will Deacon" , , Rob Herring , Frank Rowand , , Jonathan Corbet , CC: Zhen Lei , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou Subject: [PATCH v17 10/10] kdump: update Documentation about crashkernel Date: Fri, 10 Dec 2021 14:55:33 +0800 Message-ID: <20211210065533.2023-11-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211210065533.2023-1-thunder.leizhen@huawei.com> References: <20211210065533.2023-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211210_065652_006589_AB2992BF X-CRM114-Status: GOOD ( 15.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Chen Zhou For arm64, the behavior of crashkernel=X has been changed, which tries low allocation in DMA zone and fall back to high allocation if it fails. We can also use "crashkernel=X,high" to select a high region above DMA zone, which also tries to allocate at least 256M low memory in DMA zone automatically and "crashkernel=Y,low" can be used to allocate specified size low memory. So update the Documentation. Signed-off-by: Chen Zhou Signed-off-by: Zhen Lei --- Documentation/admin-guide/kdump/kdump.rst | 11 +++++++++-- Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++-- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index cb30ca3df27c9b2..d4c287044be0c70 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -361,8 +361,15 @@ Boot into System Kernel kernel will automatically locate the crash kernel image within the first 512MB of RAM if X is not given. - On arm64, use "crashkernel=Y[@X]". Note that the start address of - the kernel, X if explicitly specified, must be aligned to 2MiB (0x200000). + On arm64, use "crashkernel=X" to try low allocation in DMA zone and + fall back to high allocation if it fails. + We can also use "crashkernel=X,high" to select a high region above + DMA zone, which also tries to allocate at least 256M low memory in + DMA zone automatically. + "crashkernel=Y,low" can be used to allocate specified size low memory. + Use "crashkernel=Y@X" if you really have to reserve memory from + specified start address X. Note that the start address of the kernel, + X if explicitly specified, must be aligned to 2MiB (0x200000). Load the Dump-capture Kernel ============================ diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9725c546a0d46db..91f3a8dc537d404 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -783,6 +783,9 @@ [KNL, X86-64] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. + [KNL, ARM64] Try low allocation in DMA zone and fall back + to high allocation if it fails when '@offset' hasn't been + specified. See Documentation/admin-guide/kdump/kdump.rst for further details. crashkernel=range1:size1[,range2:size2,...][@offset] @@ -799,6 +802,8 @@ Otherwise memory region will be allocated below 4G, if available. It will be ignored if crashkernel=X is specified. + [KNL, ARM64] range in high memory. + Allow kernel to allocate physical memory region from top. crashkernel=size[KMG],low [KNL, X86-64] range under 4G. When crashkernel=X,high is passed, kernel could allocate physical memory region @@ -807,13 +812,15 @@ requires at least 64M+32K low memory, also enough extra low memory is needed to make sure DMA buffers for 32-bit devices won't run out. Kernel would try to allocate at - at least 256M below 4G automatically. + least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. - + [KNL, ARM64] range in low memory. + This one let user to specify a low range in DMA zone for + crash dump kernel. cryptomgr.notests [KNL] Disable crypto self-tests